Film feeding mechanism for films having sound track



Feb. 25, 1936. 2,031,756

FILM FEEDING vMEGHANISM Fon FILMS HAVING lspuma TRACK E'. BQFCKING Fil'ed March 8, 1934 .3 Sheets-Sheet 1 Iii lil.

mlllll .I I K ATTORNEY Feb. 25, 1936. f E. BQEcKiNG 2,031,756

FILM FEEDING MEGHANISM FOR FILMS HAVING SOUND TRACK l Filed March 8, 19554 3 Sheets-Sheet 2 ATTORNEY Feb. 25, 1936. E. BoEcKlNG 2,031,756

FILM FEEDING MECHANISM OR FILMS HAVING SOUND TRACK Filed-March 8, 1954 s sheets-sheet :s

INVENTOR A E vvd/J Fg eckr'ng ATTORNEY y l Patented Feb. 25, 19A36 l UNITED STATES lPATENT OFFICE FILM FEEDING MECHANISM FOR FILMS f HAVING SOUND TRACK Application March-8, 1934, Serial No. 714,571 Y 11 Claims.

This invention relates to new and improved mechanism for -feeding or pulling a film at constant speed, for instance through a sound recording or reproducing mechanism, or similar device. The invention has been developed and is especially useful in connection with machines for exhibiting talking motion pictures, though .it is also useful wherever a film should travel at a uniform speed, as is particularly desirable and important in connection with recording, printing and reproducing of sound records.

, 'Ihose familiar with talking motion pictures 'will appreciate the importance of feeding the film at a uniform speed through the recording, printing or reproducing devices in ordr to obviate rasping or other objectionable noises in the speaker and in order to simulate insofar as possible the original tones, and they will also understand the difcultles in the path of improvements in this field.

A feature of theA present-invention is to pro- -vide improved apparatus for the purposes mentioned.

Another feature of the invention resides in the provision in apparatus of this character of novel and superior mechanism for controlling the feeding of a film. 1

Still another feature is the provision of a novel driving mechanism for certain of the sprockets, which mechanism is capable of4 relieving the film of jolts or jerks which are probably due principally to imperfectly cut or worn gear teeth, or to fluctuations in the power supply, or both. A more specific feature resides in the provision of novel and improved mechanism for placing a lm'" under tension or drag in advance of the sound device or gate, or in other Words for promoting a uniform 'feed of the film in front of a definite point.

Still another feature is the provision of such mechanism which is reasonably simple and inexpensive to manufacture, eiiicient in operation and durable in service.

A further feature resides in providing improved guiding mechanism for properly aligning the film with a soundrecording. printing or reproducing device.

Other features, objects and advantages of the y invention will be pointed out or become apparent o in `connection with the following detailed descriptin'of one form of construction illustrating `the invention, `reference being 4had to the accompanying dn'aiwings, wherein:

l Fig. 1 is a side elevation, partly in section, oi.' 55: onelorm of mechanism in accordance with the invention, the supporting frame being here omitted;

Fig. 2 is an elevation, also partly in section, o! the mechanism shown in Fig. 1, looking from the front or left hand side of Fig; 1, the intermittent'mechanism and a portion of the sound device being omitted;

Figs. ,3V and 4 are vertical sections, on enlarged scale, of certain portions of the mechanism illustrated in Figs. 1 and 2; 1

Fig. 5 is a side elevation, partly in section, of 0 another portion of said mechanism; 1

Fig. 6 is a vertical section taken on the line 6 6 of Fig. 5, looking in the direction of the arrows; and l5 Fig. 7 is a vertical section of another portion of said mechanism.

In the construction illustrated in the drawings, a film sprocket I0, driven from the star wheel I I of Geneva gearing, is provided i'or pull- 20 ing a lm I2 through a picture projecting portion (not shown) of a motion picture projecting machine, as is common practice where the same lm contains both pictures and a sound record or track. However, if the film I2 is employed only 25 for a sound record, as where the pictures are on a. separate film, the parts Ill and II are not required for the film containing the sound track. Passing from sprocket l0. the fllm I2 forms a loop I3 between the sprocket' I2 and a friction 30 drag sprocket I4. In order to permit proper framing of the pictures, where they are on the same lm as the sound track. and where the picture projecting devices are above the intermittent sprocket I, the intermittent mechanism, 35 sprocket Ill and sprocket i4 may all be mounted for horizontal sliding in any convenient manner, so that they are all movedtogether the desired distance to draw the nlm down and thus bring a given picture into frame with an aperture o plate (not-shown) before the machine is started, Possible end positions of the sprocket I4 are shown in dot and dash lines in Fig. 1. In this manner, provision may be made for framing pictures while preserving the desired length of loop I3. and at the same time for enabling positivev engagement of the sprocket Il with the film for purposes hereinafter indicated. However, since the present invention is useful in connection with other types of lm framing de- 50 vices, and since means are described and claimed elsewhere i'oraccomplishing the horizontal movement of the parts. these need not be described in detail herein.

As best Ashown in F18. 3,.the sprocket I4 may M advantageously be mounted in the following manner. For instance, it may be secured to a bushing I5 which is journaled on a shaft I6, this shaft being mounted in any suitable portion I`I of the machine and secured against rotation, for instance by a set-screw IB. Secured in any suitable manner to shaft IS is a collar I9, with which is engaged, as by a pin 2 I, a friction disc 2D which may be formed of felt, cork, rubber composition, or other yielding material adapted to bear against an end face of the sprocket and act as a friction brake or drag, in combination with other parts hereafter described. Opposite the other end of the sprocket I4 and free on shaft I6, there is provided a shouldered collar 22 to which is secured, as by pin 2Ia., a second friction disc 20a, which may lie Within a recess 23 in the sprocket.

, The collar 22 may be maintained against turning with respect to the shaft, while being permitted to slide therealong, by means of a keyway 2lb and pin 2 Ic. Threaded onto the end of shaft I6 is a shouldered nut 24. A coil spring 25 is interposed between this nut and collar 22 and is supported on their shoulders. A headed bolt 2B is threaded into the end of shaft IB and bears against nut 24, to lock the latter against rotation. A clearance is provided between the end of shaft I6 and the head of bolt 26 to permit requisite movement of the latter.

In this manner there is provided a simple and effective construction for adjusting the force imposedon the sprocket I4 by friction discs 20 and 20a. That is to say, by turning up the nut 24, the force exerted on spring 25, and consequently the friction against sprocket I4, may be adjusted to the proper, desired amount. When the nut 24 is in proper position either for initial setting or to compensate for wear of discs 2D after long use, the bolt 26` may be turned up against nut 24 and acts as a lock-nut. While the sprocket I4 and co-operating parts furnish an' excellent means for the purposes mentioned, it will be appreciated that other retarding or loop-forming mechanism might be employed. That is to say, other suitable devices might be substituted for the sprocket I4, provided they are capable of exerting a drag upon the lm and of maintaining a loop I3 between the intermittent device and the sound gate.

From the sprocket I4 the film preferably passes into engagement with the under side of an idler sprocket 30 (Figs. 1, 2 and '7), secured in any suitable vmanner to a shaft 3| which is journalled in a bearing 32, for instance by means of bushings 35. This bearing' may conveniently be formed integral with an upstanding rigid portion 33 of the frame of the machine. If desired a disc or revolving member 34 of the character shown may be secured to the shaft 3| at a suitable point, for instance by pin 36. 'I 'he idler sprocket is effective, especially when employed in combination with other features of the present improvement, for taking slack out cf the film in advance I However, if desired, a roller may of the film gate. replace sprocket 30.

It will be appreciated that in this construction the film engages the sprocket teeth, of sprocket I4 and of sprocket 30, so that each of these sprockets is rotated bythe film. A positive drag is thus imposed op the film. v

The film passing from beneath sprocket 30 is preferably engaged by a device for edge guiding and precisely aligning the film with the sound gate and preferably for also exerting a drag on the film, in addition to the drag imposed by the accijns with respect thereto and is also provided with a portion 43 and a flange portion 44, similar and opposed to like portions of sleeve 42. The end of sleeve 45 may be bevelled as at 46 and may be urged against portion 43 on sleeve 42 (when no film is in the machine) by a light coil spring 41` interposed between a collar 48 and the large end of sleeve 45. The collar 48 is slidable axially of shaft and is urged against the small end of sleeve 42, which protrudes beyond the large end of sleeve 45, by means of a relatively heavy coil spring 49 bearing against the rigid frame portion 33. A headed bolt 55 is threaded into the righthand end of shaft 4I) and through its head engages the sleeve 42 and holds the parts in assembled relation. A suitable clearance is provided between the right-hand end of shaft 40 and the head of bolt 50 to permit desired lateral adjustment of the members 42 and 4f, the adjustment being accomplished by turning the bolt to urge these members against the coil spring 49 which is thus placed under compression. The force of spring 49 may be sufficient to prevent sleeve 42 from turning under normal operating conditions',

or a pin 40a may cooperate with slots 42a in the sleeve 42 and shaft 4I), to prevent rotation therebetween. The sleeve is preferably held against rotation by means of an arm 5I secured to frame member 33 and a pin 52, which is secured to member 45 and slides into a co-operating hole in karm 5I.

There is thus provided a device for precisely aligning the lm with the sound gate, and at the same time for exerting a friction drag on the iilm.

More particularly, it will be noted that the length of member 45 is such that when a standard-size film is to beV placed between the opposed flanges 44, the member 45 has to be moved slightly t0 the left against the action of light spring 4'I in order to accommodate the film, thus providing a 'clearance between end 46 of the member 45 and the portion 43 of member 42. During operation of the machine, the film is thus yieldingly urged.v

against the right-hand ange 44, which latter is firmly held against the rigid head on bolt by theaction of heavy spring 49. By simply turning the bolt 50, in the proper direction, the member 42 may be accurately adjusted to a position where its ange 44 engagesthe edge of the fllmadiacent the sound-track (compare Fig. 2), and thus, with the assistance of the spring-pressed member 45, accurately aligns the sound-track with respect to the film gate, immediately in advance of the gate. Upon adjusting the member 42, whether the lm is then in the machine or not, the member 45 requires no `separate adjustment.

45 is supported on the sleeve 42 for sliding axially When the lm is properly threaded through 'y the machine, it lies against the curved surfacesI on portions 4,3, over a substantial portion of their circumferences, for instance, as shown in Fig. 1, and is pulled over these surfaces, by mechanism hereafter described. Where tfie member -42 is held against rotation, for instance by heavy spring 4 9, and the member 45 is also held against rotal drag imposed on the iilm tion, for instance as described. there is a definite @y these members, directly in advance of the film gate, as is highly advantageous in order to prevent slack in the film opposite the gate and thus provide a precise cooperation' between illm and gate.

'Ihe sound device need not be described in detail as it may take any convenient, known form, and include a source of lightl", a photo-electric cell 88, and a gate 81 having an\aperture 88 with which the sound track of the film is aligned. -The illm is preferably drawn taut along the surface of the gate by means of a sound sprocket 88, which pulls the film against the substantially constant drag imposed on it by means of the foregoing character. The sprocket 88 is advantageously driven at a substantially constant speed. For driving sprocket 88, mechanism of the following character results in a number of advantages. in-

cluding uniformity of speed, as will become apparent.

For example, the sprocket 88 may be secured to onel end of a shaft 8| (Fig. 2) which is journalled in the frame 88 in any convenient manner, and a gear 82 may beI secured to the other end of this shaft and be engaged by a worm gear 83 (Figs. l and 'I'he worm gear 88 is journalled on a shaft Il which may be driven by an electric motor 88, directly or through a suitable or known type of filter (not shown), interposed between the motor 88 and shaft 88. Worm 88 is provided with a reduced sleeve portion 88, upon which there is mounted a disc or revolving member 81 having a rim 88 and a hub 88.

For causing the disc or revolving member 81 to rotate with the worm 88, and at the same time. for eliminating flutter between these parts and the drive shaft 88, as is particularly desirable where there is a resilient filter, such as is hereafter described, between the driving and driven elements, mechanism of the following character may advantageously be employed. For example, a bifurcated or pronged pin 18 extends into aligned openings in hub 88 of the revolving member 81 and in sleeve 86 ofthe worm 8l, the ends of the prongs being tapered or curved and being yieldingly urged against the curved suface of shaft '84 by a leaf or flat spring 1i, one end of whichA bears against or may be secured to hub 88 and the other end of which engages the outer end of pin 1D. 'I'he spring 1I is engaged by a bolt 12. and' acts as a lever, the force applied to the pin being adjusted by turning the bolt in the proper direction. The force applied may advantageously be sufficient as to spreadJ the prongs to caus'e them to engage the walls of the openings in which they lie, but should not be so great as to prevent proper operation of the resilient filter or .as to prevent backing out of the pin to avoid Jamming of the parts under an excessive overload.

To the shaft 8l, at the opposite side of disc 81 from the hub 68, there is secured. as by means of a bolt 14, a collar 13 (Figs. 1 and 2). In this collar there are mounted'in any convenient manner a pair of opposed radial arms 15, to the outer ends of each of lwhich are attached ends of pairs of coil springs 18, the other ends of these springs the sleeve of worm 88, which drives gear ItonA sprocket shaft 8|, the worm 88 being capable of rotational movement with respect to shaft 8l.

'I'here are also provided, in the mechanism shown, means for positively driving the worm 88 during starting up of the machine. A worm gear 88, for additional purposes hereafter' mentioned, may be secured to shaft 64, by means of a bolt 8 I and be provided with one or more feet v82, each of which extends into a slot 83 in the end of worm 88. The 4slots are preferably sufficiently wide to permit the resilient drive or filter to function as described during ordinary running conditions, so

that jerks or jolts in the driving mechanism-are not transmitted to the sound sprocket 88. At the same time the feet 82 and slots 83 cooperate to positively drive the worm .83 during starting up,

thus relieving the springs 18 of excessive forces which would tend to weaken them or wear them out. After the parts are running the springs 18 take up the drive, and feet 82 are normally out of contact with the ends of slots 83, vsave possibly,

if desired, under severe jolts of shaft 84. A

spacing collar 84 may be provided to prevent end play of the worm 83, and this collar may seat on suitable shoulders 81, 88 formed on worm 88 and worm gear 80.'

The worm 88, in addition to cooperating with worm 83 as described, serves to drive gear 88, which is secured to a shaft 88 on which is mounted a take-up sprocket 89 for feeding the film from sprocket 88 to a take-up reel (not shown). while providing slack portion between the sprocket 88 and sprocket 89, as is desirable.

There is thus provided a superior mechanism in which a simple and eiiicient driving mechanism pulls the film forward at a substantially constant speed, the resilient drive between the power shaft and the disc 61- being adapted to damp .out or filter uneven power impulses, thus preventing them from being transmitted to the sprocket which pulls the film forward. A minimum number of gears and other parts are required in the mechanism and the construction is sturdy and durable.V By applying the disc 81 to the driven member 83 additional smoothness may be achieved. Furthermore, by the positive drive provided during starting up, the resilient device to weaken it or. Wear it out. l

In addition, the mechanism includes means for exerting a highly constant drag on the film, thus tending to take slack out of the film and place it is relieved of excessive stresses which would tend v under a uniform tension in advance of the sound 'may not in all cases be required. So, too, the

idler sprocket constructionn aids the other parts in imparting a smooth travel to the film. The segregation of these features from the driving mechanism also appears to aid in promoting the desired advantages. While all these features contribute to the achievement of a constant film feed, it will be appreciated that certain of them may be combined or even omitted under some conditions, while the desired advantages may still besecured. n

An-excellent and positive alignment of the film with a, sound device or othervmechanism is produced by edge guiding means of the character described, particularly as the film is positively aligned on one edge while allowance is made at the other edge for some roughness or unevenness of thefilm. Moreover, adjustment of the guiding means is readily accomplished.

A particular feature of the present mechanism resides in the dampening device associated with the resilient driving means. The advantages of this construction may be summarized by reference to Figs. 2 and 6. By adjusting the force on pin 10, undesired flutter between the driving member (shaft 64) and the driven members (68 andv) may be eliminated. In other words, if the resilient means (springs 16) tend to cause vibrations, these may be clamped out by the device of the character described.

In addition, the mechanism is simple andinexpensive to build and assemble, is handy to the operator for adjustments and repairs, and involves minimum possibilities of wear and breakdown.

'I'he terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding.

any equivalents of the features shownand described, or portions-thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

l. In a machine of the character described for feeding a film at constant speed past a fixed point, means for imposing a friction drag on said fllm, means for edge guiding the film immediately in advance of said point, an idler sprocket operatively interposed between the first-named means and the second-named means, and means to cause the film to travel into and out of engagement with each of said means.

2. In a device of the character described, pposed members for edge guiding a film, means to urge said members toward each other, means for adjusting the lateral alignment of both of said members simultaneously, and means for maintaining them stationary.

3. In mechanism of the character described, a device for preventing flutter between an annular member and a member therewithin, comprising a bifurcated memberV having tapered end portions adapted to bear against said second member, means in` said annular member for receiving the bifurcated member, and yielding means adapted to exert a force on said bifurcated member to urge said tapered end portions against said second member.

4. In mechanism of the character described, including sound mechanism, a sprocket for drawing a film past the sound mechanism, a sprocket for engaging the film leaving the first sprocket, a

shaft, 'a gear carried by said shaft and rotatable with respect thereto, resilient means for driving said gear from said shaft, driving connections between said gear and said first-named sprocket, a

gear secured to said shaft, and driving connections between said gear and said second-named sprocket.

5. In mechanism of the character described including sound mechanisrma sprocket for drawing a film past sound mechanism, a sprocket for engaging the film leaving the first sprocket, a shaft, a gear carried by said shaft and rotatable with respect thereto, resilient means for driving said gear from said shaft, driving ccnnections between said gear and said first-named sprocket, a gear secured to said shaft, and driving connections between said gear and said secondnamed sprocket, said gears being provided with a tongue and slot connection whereby the second gear positively drives the first under loads on the first in excess of normal.

6. In mechanism of the character described, means to exert a drag on a iilm,means to align the film laterally, means to pull said film, means to receive said film from the pulling means, and means comprising a single shaft for operating said pulling means and receiving means.

7. In mechanism of the character described, means to exert a drag on a film, means to align the film laterally, means to pull said film, means to receive said film from the pulling means, means comprising a single shaft for operating said pulling means and receiving means. said last named means including a resilient connection between said shaft and said pulling means, and said pulling means comprising a disc on the driven` side of resilient connection.

8. In a machine of the character described.`

power means, a shaft rotated by said means, a worm journalled on said shaft, a disc secured to the Worm, a. sprocket operatively connected with said worm, and resilient means for driving said disc from said shaft.

9. A device of the character described for edge guiding a film, comprising relatively movable members adapted to engage the edges of a film. relatively light yielding means for urging one of said members toward the other and against an edge of the film, an adjustable stop for determining the alignment ofthe other of said members, and relatively .heavy yielding means for utrging the other of said members against said s op. l

10. In sound-on-lm mechanism of the character described, intermittent means, constant speed means for drawing aiilm past a fixed point, loop-forming means operatively interposed between said intermittent means and said fixed point, and separate drag means interposed between the loop-forming means and said point.

1l. The combination as claimed in claim 10, wherein said last named means comprise an idler sprocket and stationary means for edge-guiding the film.

EWALD BOECKING. 

